TRT and Prostate Health: Separating Myth from Fact

Medically reviewed by Dr. Michael Koehler, MD | Affinity Whole Health

For decades, many men were told that raising testosterone levels could cause or worsen prostate cancer. At Affinity Whole Health, we follow the most current evidence so you can feel confident and informed. This guide explains the science, what we monitor, and how we keep your prostate safe while you enjoy the full benefits of TRT.

How the “TRT Causes Prostate Cancer” Myth Started

The concern originated from a 1941 study by Drs. Charles Huggins and Clarence Hodges published in Cancer Research. In this early research, men with advanced metastatic prostate cancer underwent castration or estrogen therapy, which lowered acid phosphatase levels (a blood marker used at the time) and led to clinical improvement in many patients. Testosterone was administered to only 3 men with advanced metastatic prostate cancer. Detailed results were reported for just 2 of these patients. One of the 2 had already been castrated. The key conclusion that testosterone “activated” prostate cancer was therefore based primarily on data from a single non-castrated patient, in whom acid phosphatase levels rose during 18 days of injections (with wide fluctuations noted before and after treatment).

This study had several major scientific limitations that were largely overlooked for decades:

• Extremely small sample size for the testosterone arm (only 3 men total, with detailed data on 2).

• All participants had late-stage, metastatic prostate cancer — not early-stage disease or healthy men.

• Testosterone was given only to men whose testosterone levels had already been driven to nearly zero by castration (except for the one non-castrated case).

• The study only measured short-term changes in a single blood marker (acid phosphatase), not actual tumor growth, cancer incidence, or cancer progression in a normal prostate.

• There was no long-term follow-up, no control groups for comparison in the testosterone arm, and no assessment of clinical outcomes beyond the blood marker.

Despite these critical flaws, the results were dramatically over-extrapolated to suggest that giving testosterone to any man would cause or accelerate prostate cancer. This unjustified leap became entrenched medical dogma for over 70 years.

Dr. Morgentaler’s Groundbreaking Work and the Saturation Model

Affinity Whole Health follows the evidence-based approach pioneered by Dr. Abraham Morgentaler — the urologist who disproved this long-held myth. Dr. Michael Koehler, our medical director, studied under Dr. Morgentaler and completed his Morgentaler Method fellowship. His landmark 2006 review published in European Urology described the old belief as a modern myth.

Later studies, including Dr. Morgantaler’s own clinical series and the saturation model he helped develop, confirmed that men with low testosterone who received TRT did not experience higher rates of prostate cancer — and in many cases had better outcomes because they were monitored closely.

What the Latest Evidence Shows

Modern research supports the safety of TRT in appropriately selected men:

• A large 2023 randomized trial (TRAVERSE) prostate safety analysis found no increase in prostate cancer or other prostate-related events compared with placebo.

• A 2024 meta-analysis of 28 randomized controlled trials concluded that testosterone therapy does not increase the risk of prostate cancer or worsen prostate parameters in men without known prostate cancer at baseline. 

In fact, some data suggest that men with untreated low testosterone may actually have a higher risk of aggressive prostate cancer later in life.

What We Monitor for Prostate Health on TRT

We take a proactive, guideline-based approach:

• Baseline PSA (prostate-specific antigen) before starting TRT

• Repeat PSA with full labs every 4-5 months while on TRT

• We watch for any abnormal PSA levels and refer to urology when appropriate

Myths vs. Facts

Myth: TRT causes prostate cancer.

Fact: Decades of data, including Dr. Morgentaler’s work and large modern trials, show no increased risk when men are properly screened and monitored.

Myth: Men with a history of prostate cancer can never use TRT.

Fact: In carefully selected men with treated, low-risk prostate cancer, TRT can be used safely after shared decision-making with urology.

Myth: Higher testosterone always means a bigger prostate or worse urinary symptoms.

Fact: Most men on TRT notice no change or even improvement in urinary flow because better pelvic blood flow and muscle tone can help.

Conclusion

Testosterone therapy does not cause prostate cancer — a myth that Dr. Morgentaler disproved and that modern studies continue to confirm. With proper screening and monitoring, TRT is safe for the vast majority of men and can dramatically improve energy, strength, mood, and quality of life.

At Affinity Whole Health, prostate health is a core part of our personalized TRT programs. We bring the knowledge from Dr. Morgentaler’s work to every patient we treat. If you have questions about your PSA, prostate risk, or whether TRT is right for you, contact our office today. We’re here to help you feel your absolute best — safely and confidently.

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Disclaimer: This article is for educational purposes only and is not intended as medical advice, diagnosis, or treatment. Compounded medications from Affinity Whole Health are prepared in FDA-registered compounding facilities and are not FDA-approved drugs. All prescriptions require a provider consultation and lab work. Always consult a licensed healthcare provider before medications or treatment plans. Individual results vary.

Affinity Whole Health does not offer paid trials.